MC9S12G FREESCALE [Freescale Semiconductor, Inc], MC9S12G Datasheet - Page 874

• Manufacturer Part Number: MC9S12G
• Description: Ignores external trigger. Performs one conversion sequence and stops.
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

96 KByte Flash Module (S12FTMRG96K1V1)
25.3.2.2
The FSEC register holds all bits associated with the security of the MCU and Flash module.
1
All bits in the FSEC register are readable but not writable.
During the reset sequence, the FSEC register is loaded with the contents of the Flash security byte in the
Flash configuration field at global address 0x3_FF0F located in P-Flash memory (see
indicated by reset condition F in
phrase containing the Flash security byte during the reset sequence, all bits in the FSEC register will be set
to leave the Flash module in a secured state with backdoor key access disabled.
874
KEYEN[1:0]
Loaded from IFR Flash configuration field, during reset sequence.
RNV[5:2]
SEC[1:0]
Offset Module Base + 0x0001
Reset
Field
This document is valid for the S12G96 and the S12G128 device. All information related to other devices is preliminary.
7–6
5–2
1–0
W
R
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of backdoor key access to the
Flash module as shown in
Reserved Nonvolatile Bits — The RNV bits should remain in the erased state for future enhancements.
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in
Flash module is unsecured using backdoor key access, the SEC bits are forced to 10.
Flash Security Register (FSEC)
F
7
1
KEYEN[1:0]
F
= Unimplemented or Reserved
6
1
1
Preferred KEYEN state to disable backdoor key access.
KEYEN[1:0]
Figure 25-6. Flash Security Register (FSEC)
00
01
10
11
MC9S12G Family Reference Manual,
Figure
Table
Table 25-9. FSEC Field Descriptions
Table 25-10. Flash KEYEN States
F
5
1
25-10.
25-6. If a double bit fault is detected while reading the P-Flash
Status of Backdoor Key Access
F
4
1
RNV[5:2]
Description
DISABLED
DISABLED
DISABLED
ENABLED
F
3
1
1
Rev.1.01
F
2
1
Freescale Semiconductor
Table
F
1
1
Table
SEC[1:0]
25-4) as
25-11. If the
F
0
1